It is often necessary to remove and/or change the tip of a spray nozzle for various reasons, such as inspection of the parts and cleaning if required because of stoppage, or clogging, or any other type of blockage. The nozzle tip may be replaced, or a different type substituted for a different type of spraying operation.
The usual threaded type connection utilized with spraying apparatus between a nozzle body and a spraying tip is subject to obvious limitations. When a non-axial spray direction is used, the threaded connection requires adjustment of the direction each time the nozzle is removed. Some spraying apparatus is not stationary and this requires that tools be provided at all of the various locations where the apparatus may be used, or otherwise transported with the apparatus to the site. Just the operation of removing and reapplying a threaded connection is unduly time-consuming, especially where the spraying apparatus may have multiple nozzles.
In the past, quick disconnect nozzles have been provided such as U.S. Pat. No. 4,185,781 wherein a separate seal member was provided and a separate pressure-applying spring also included. In other types of prior nozzles, additional parts were required in order to couple the nozzle tip with the nozzle body, and such coupling components resulted in a significant loss of time just in handling the multiple parts, and especially where, as often happened, some of the parts may have been lost, or misplaced during disassembly, or as the parts were attempted to be reassembled. These problems were especially acute where the spraying apparatus was of the mobile type. Some quick disconnect nozzles relied upon frictional engagement of the spray tip with the nozzle body and this necessitated very precise machining, or molding tolerances in the manufacture of such parts. This type of engagement was also undesirable for non-axial spraying directions inasmuch as the spray tip had to be adjusted for the proper direction each time such nozzles were assembled, or disassembled.
More recently, U.S. Pat. No. 4,438,884 discloses a quick disconnect spray nozzle comprised of a spray tip and a nozzle body and a combination seal and pressure exerting member between the body and the nozzle tip. The combination pressure exerting seal member is resilient and is mounted in the nozzle body concentric with the nozzle bore and when the nozzle tip is mounted in the body, a sealing ring on the tip abuts an end of the seal member around the bore, thus providing a seal between the parts and also compressing the seal member, whereby pressure is applied between the nozzle body and the tip to maintain the locked condition of the tip in the body.
The combination member thus eliminates any need for a separate spring and a separate sealing member and the single member functions both as a seal and as a spring, or pressure-exerting member, to provide substantial advantages over earlier nozzles using the separate spring and separate seal. In addition to acting as a seal between the nozzle body and the spray tip the present sealing member acts also to seal the assembly against the entry of contaminants such as sand or other abrasive materials between the tip and the body housing which would cause excessive wear and possibly destroy the sealing properties of the seal member.
Quick disconnect nozzles of the type shown in U.S. Pat. No. 4,438,884, assigned to the same assignee as the present application, are commonly used for agricultural purposes. Large numbers of such nozzles are mounted on a common spray boom. Such nozzle assemblies may also have a spray tip retaining cap which is positioned onto a nozzle body. A sealing member interposed between the cap and body serves to provide a fluid-tight seal between the two members and to bias the cap in its assembled condition. In assembling the cap, it is commonly necessary to force the cap against the biasing force of the sealing member and then twist the cap into an assembled or locked position. Because of the location of the nozzles on the boom, and the multiplicity of such nozzles, it can be cumbersome, difficult, and tiresome to disconnect and reassemble large numbers of such nozzles.
In addition, after removal of the nozzle caps and spray tips from the nozzle assembly, it often is desirable to direct pressurized fluid through the nozzles in order to clean and flush out any contaminates that have accumulated. With the cap and spray tip removed, however, such flushing with pressurized liquid frequently causes the sealing members to be dislodged and to be forcibly ejected from the nozzle body, making it necessary to locate the sealing members and then replace them. In addition, if the nozzle bodies include vanes for imparting whirling motion to the discharge spray, it frequently is necessary to disassemble the vane from the nozzle in order to permit effective cleaning, and heretofore, this also has been tedious and cumbersome.
Moreover, in many instances it is important that the quick disconnect nozzle be reassembled with the nozzle tip in predetermined angular orientation. Because of the awkwardness and force required in overcoming biasing forces of sealing members and springs, and because of the awkwardness in the location of the spray nozzle assembly on the boom, problems have also occured in reassembling the nozzle tip with the prior orientation.